Stability of sulfadiazine oral liquids prepared from tablets and powder.

PURPOSE To assess the stability of sulfadiazine (SDZ) oral liquids prepared from tablets and powder at two temperatures. METHODS Solutions of SDZ 200 mg/mL were prepared from commercially available 500 mg tablets and powder in sterile water for irrigation. They were stored in amber glass bottles at 4 degrees C and 23 degrees C. The concentrations of SDZ were determined in duplicate by high-performance liquid chromatography at 0, 1, 3, 7 and 14 days. The initial and final pH of solutions was compared. The recovery of SDZ from tablets was determined. A loss exceeding 10% of the initial concentration of SDZ was considered excessive degradation. RESULTS The recovery of SDZ from tablets was 100 +/- 3%. The initial pH values were significantly different between solutions prepared from tablets and powder, 6.9 and 9.8 respectively. No significant difference was found between initial and final pH values for the two all formulations. Detectable change in odor was observed for the solutions stored at 23 degrees C. The solution prepared from powder was stable 3 days stored at 4 degrees C. Other formulations lost over 10% of the initial SDZ concentration within 2 days. CONCLUSIONS SDZ 200 mg/mL oral solution prepared from powder could be used to facilitate drug administration to very young children by nurses but by taking account of its fast degradation.